1. Field of the Invention
The present invention relates to an art of managing shared documents. More particularly, this invention relates to a data processing system for storing shared documents in a storage unit using a local area network (LAN) such as a group ware and for managing them.
2. Description of the Related Art
In the past, a data processing system for managing shared documents using a LAN is focused on controlling a process that when a plurality of users contend with one another about access to one shared document, grants an access authority to a single user, or on controlling a process that when one user is granted an access authority, suspends temporarily access authorities of other users or excludes the access authorities.
In such a document sharing-related art, when a certain user had gained an access authority, referred to a shared document, and updated the shared document, the fact that the shared document has been updated should be notified together with the contents of update, if necessary, for the sake of users' (including users who have previously accessed to (referred to/updated) the shared document) convenience. In this case, the user who has updated the shared document should autonomously notify other uses who have accessed the shared document previously of the fact.
According to the aforesaid prior art, as long as users merely refer to a shared document, no problem occurs. However, when a user who has referred to a shared document is different from a user who has updated the shared document, a problem described below occurs.
For example, after a certain person (a first user) has referred to a shared document, another person (a second user) updates the shared document. In this case, when accessing the shared document again for the purpose of updating, the first user may proceed with work using previous information (or information that has not been updated) while being unconscious or unaware of the fact that the shared document has previously been updated.
When a user has updated a shared document, there is no problem as long as the user can notify other users of the fact using mail messages or the like. According to the conventionally known art, since a user who has updated a shared document does not have means for accurately finding out which users have accessed the shared document previously, the user cannot notify other users of the fact that the shared document has been updated. Consequently, as mentioned above, a user who has accessed the shared document may proceed with work using information that has not been updated (incorrect information). This is because even if the shared document has been updated, the user may be unaware of the fact.
As mentioned above, in the conventionally known art related to document sharing, no consideration is taken into means for automatically notifying other users of the fact that a shared document has been updated. Users cannot therefore acquire the latest correct information concerning a shared document. This brings about an incident that the shared document is updated according to incorrect information. Eventually, the users are put to inconvenience in utilizing the shared document. This is not preferable.